Plate heat exchanger from polytetrafluoroethylene

ABSTRACT

A PLATE HEAT EXCHANGER WHICH CONSISTS OF PLATES AND SEPARATING SHEETS MADE FROM POLYTETRAFLUOROETHYLENE, THE PLATES BEING PROVIDED WITH CHANNELS ON ONE OR BOTH SIDES. THE CHANNELS OF ADJACENT PLATES ARE SEPARATED BY SHEETS MADE FROM POLYTETRAFLUOROETHYLENE.

May 15, 1973 L SANBERGER ETAL 3,733,244

PLATE HEAT EXCHANGER FROM POLYTETRAFLUOROETHYLENE Filed Feb. 16, 1971 3 Sheets-Sheet 1 OOOOOOOO 8 f, mb 3 A Q C Q C. .D N w k m H T. N m m a S T 5 C n A w w s w\ L INVENTORS LUDWIG SANBERGER GOTTFRIED BURGSTALLER May 15, 1973 L. SANBERGER ETAL 3,733,244

PLATE HEAT EXCHANGER FROM POLYTETRAFLUOROETHYLENE Filed Feb. 16, 1971 3 Sheets-Sheet 2 o o {o i 5 P SECTION d-d g \l'" g SECTION e-e s 7 :Q .AL \y SECTION f-f Q V 3 g T i\ 6 INVENTORS LUDWIG SANBERG ER GOTTF RIED BURGSTALLER May 15, 1973 L. SANBERGER ETAL 3,733,244

PLATE HEAT EXCHANGER FROM POLYTETRAFLUOROETHYLENE Filed Feb. 16, 1971 3 Sheets-Sheet 5 HH 1 I ll 3 I w//////// FIG. 4

INVENTORS LUDWIG SANBERGER GOTTFRIED BURGSTALLER United States Patent Office 3,733,244 Patented May 15, 1973 3,733,244 PLATE HEAT EXCHANGER FROM POLYTETRAFLUOROETHYLENE Ludwig Sanberger and Gottfried Burgstaller, llurgkirchen (Alz), Germany, assignors to Farbwerke Hoechst Aktiengesellschaft vormals Meister Lucius & Bruning, Frankfurt am Main, Germany Filed Feb. 16, 1971, Ser. No. 115,493 Claims priority, application Germany, Feb. 17, 1970, P 20 07 033.1 Int. Cl. F28f 3/00 US. Cl. 161-166 6 Claims ABSTRACT OF THE DISCLOSURE A plate heat exchanger which consists of plates and separating sheets made from polytetrafluoroethylene, the plates being provided with channels on one or both sides. The channels of adjacent plates are separated by sheets made from polytetrailuoroethylene.

The present invention relates to a plate heat exchanger from polytetrafluoroethylene.

To carry out the heat exchange, which is necessary in industry in a great number of different chemical processes, various types of apparatuses have been proposed, inter alia so-called plate heat exchangers. The known plate heat exchangers are made, in the first place, of corrosion resistant metallic materials of high quality.

It has been proposed to use polytetrafluoroethylene as material for the manufacture of heat exchangers to be used in aggressive and corrosive mediums, for example in US. Pat. Nos. 3,228,456; 3,277,959; and 3,315,740. These known heat exchangers are made from tubes of polytetrafluoroethylene or materials containing polytetrafiuoroethylene. In the field of plate heat exchangers, however, this material, which is difficult to work, has not yet been used.

The present invention provides a plate heat exchanger which consists of plates and separating sheets from polytetrafluoroethylene or materials containing polytetrafluoroethylene, the plates being provided with ribs and channels in such a manner that the heat exchange of two mediums led in the channels formed by the ribs takes place through the separating sheets and the plates.

The plate heat exchanger according to the invention is now illustrated with reference to the accompanying drawings in which FIG. 1 is a top view of a plate of a heat exchanger and three sectional views along lines a-a, b-b and c--c,

FIG. 2 is a top view of a plate of another heat exchanger and three sectional views along lines dd, ee and f FIG. 3 is a top view of the tube connection and FIG. 4 is a cross sectional view of the tube connection.

The individual elements of the heat exchanger can be connected in series as can be seen by section bb of FIG. 1 or in parallel as can be seen by section e-e of FIG. 2.

In both cases the heat exchanger consists of a pack comprising a plate of polytetrafluoroethylene =1 grooved on both sides, plates of polytetrafluoroethylene 2 grooved on one side only on either side and polytetrafluoroethylene sheets 3 clamped between the plates, through which sheets the heat exchange takes place. The packs of plates and sheets is held together by means of two terminal plates of steel 4 and the corresponding tie rods 5. In the terminal plates two sparings 6, 7 are provided for the connection sockets 9/10 for the inlet and outlet of the exothermic and endothermic mediums.

The sectional views show that the ribs must be exactly one on top of the other so that the separating sheet may resist, it necessary, as high as possible a differential pressure of the two mediums. As the channels may be fed in series or in parallel, the novel plate heat exchanger may easily be adapted to the most various conditions of quantity and operation, for example, the heat exchange of liquid mediums, the condensation of vapours, or vaporization processes.

Referring to FIGS. 3 and 4, the connection sockets 9/10 are pressed by means of divided rings 11/12 shifted by against polytetrafiuoroethylene plates 8, which are provided with distribution channels.

The plate heat exchangers in accordance with the invention may be manufactured-depending on the chemical or thermal stressfrom different materials or material combinations.

In the first place, besides pure polytetrafluoroethylene, which has a low coeflicient of thermal conductivity and a poor pressure resistance, there are used combinations of polytetrafluoroethylene with other materials which have higher coefiicients of thermal conductivity and withstand elevated pressures. In special cases, the plates of the heat exchanger may be manufactured completely or partially from other materials, for example ceramics, in which case the separating sheets 3 may also consist of metals or carbon.

We claim:

1. A plate heat exchanger comprising outer and central grooved plates of polytetrafluoroethylene, sheets of polytetrafluoroethylene, said outer plate having grooved channels in one surface, said central plate having grooved channels in both of its surfaces, said plates and said sheets being disposed in a pack with at least one central plate disposed between grooved surfaces of a pair of said outer plates and said sheets being disposed inbetween said plates, said grooved channels in said plates being algined and separated from each other by said sheets, terminal plates on the outer sides of said outer plates, tie means holding said assembled plate and sheets together, connecting conduit means on said terminal plates for supplying and discharging fluid from said plate heat exchanger, connecting passage means in said outer and central grooved plates for causing said fluid to flow into and out of said grooved channels, and said connecting conduit and passage means being constructed and arranged to cause the fluids between which heat is exchanged to separately flow in said grooved channels on opposite sides of said sheets whereby heat is exchanged through said sheets between said fluids.

2. A plate heat exchanger as claimed in claim 1, wherein copolymers of polytetrafiuoroethylene are used as material for the plates and separating sheets.

3. A plate heat exchanger as claimed in claim 1, Wherein the polytetrafluoroethylene contains a filler.

4. A plate heat exchanger as claimed in claim 3, wherein the filler is graphite.

5. A plate heat exchanger as claimed in claim 2 wherein the copolymers of polytetrafluoroethylene contain a filler.

6.A plate heat exchanger as claimed in claim 5 wherein the filler is graphite.

References Cited UNITED STATES PATENTS 3,282,334 1/1966 Stamlheber -466 3.277.959 10/1966 Withers 165-159 CHARLES SUKALO, Primary Examiner 

